Anchoring assembly for anchoring well equipment within a tubular well conduit

ABSTRACT

An assembly including a pressure driven positioning member releasably connected with an anchoring member. The assembly is pumped-down a well conduit and the anchoring member is set in anchoring engagement with a collar recess in the conduit where it supports attached well equipment. A resilient annular seal on the positioning member forms a sliding pressure seal with the conduit causing the member to be moved downwardly by well-head pressure and upwardly by formation pressure. The anchoring member is set and retrieved by axial movement of the positioning member which separates from the anchoring member after it is set. The positioning member may be reconnected to release and retrieve the anchoring member and attached well equipment. The positioning member may also be retrieved by a wire-line or tubing string operated device.

Brown Feb. 5, 1974 ANCHORING ASSEMBLY FOR ANCHORING WELL EQUIPMENT WITHIN A TUBULAR WELL CONDUIT [76] Inventor: Cicero C. Brown, Houston, Tex.

[22] Filed: Apr. 23, 1971 [21] App]. No.: 136,796

[52] US. Cl ..166/125, 166/121, 166/153,

[51] Int. Cl E21b 23/06, E2lb 33/126 [58] Field of Search... 166/121, 138, 123,125, 214, 166/217, 216,153

[56] References Cited UNITED STATES PATENTS 3,318,605 5/1967 9 Brown [66/187 X 3,593,784 7/1971 Brown 166/125 3,633,670 l/l972 Brown 166/125 3,670,821 6/1972 Tamplen 166/125 3,646,996 3/1972 Pearce 166/125 X 3,606,926 9/1971 Schwegman 166/214 X 3,332,494 7/1967 Scott 166/121 3,507,329 4/1970 Stone... 166/217 X 2,871,947 2/1959 Fredd 166/214 X 3,530,935 9/1970 Garrett 166/153 Primary ExaminerDavid H. Brown Attorney, Agent, or Firm-Carlos A. Torres [5 7] ABSTRACT An assembly including a pressure driven positioning member releasably connected with an anchoring member. The assembly is pumped-down a well conduit and the anchoring member is set in anchoring engagement with a collar recess in the conduit where it supports attached well equipment. A resilient annular seal on the positioning member forms a sliding pressure seal with the conduit causing the member to be moved downwardly by well-head pressure and upwardly by formation pressure. The anchoring member is set and retrieved by axial movement of the positioning member which separates from the anchoring member after it is set. The positioning member may be reconnected to release and retrieve the anchoring member and attached well equipment. The positioning member may also be retrieved by a wire-line or tubing string operated device.

22 Claims, 12 Drawing Figures PAIENIEU 51974 I 3.789.925

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laouuu A TTOENE) ANCHORING ASSEMBLY FOR ANCHORING WELL EQUIPMENT WITHIN A TUBULAR WELL CONDUIT BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to means for anchoring well equipment such as storm chokes, packers, or other equipment at a sub-surface location in a well conduit. More particularly, the present invention relates to a retrievable, pump-down anchoring assembly adapted to be set in anchoring engagement within a collar recess formed between joints in a well conduit which extends into a relative high pressure formation.

2. Description of the Prior Art Sub-surface equipment is conventionally anchored within well conduits by wire-line or tubing string operated anchoring assemblies. Often, such mechanically operated anchoring assemblies are designed to be locked within specially recessed landing nipples which are included in the well conduit. In some cases, where such nipples are not present, the mechanical anchoring assemblies are designed to be set in anchoring engagement within the collar recess formed between two mating pipe joints forming the well conduit.

When the well conduit extends into a relatively high pressure formation, setting and release of a conventional, mechanically operated anchoring assembly normally requires use of well-head equipment such as stuffing boxes and other suitable equipment which prevent loss of pressure at the well-head and simultaneously permit axial or rotative movement of the wireline or tubing string which is used to position and set the anchoring assembly. The difficulties associated with setting and retrieving well components with the use of equipment of this type are well known in the art.

Setting and retrieval of conventional anchoring means can also become particularly difficult when, in addition to requiring the use of sealing means and the like at the well surface, it is also necessary to employ multiple, axial or rotative movements to effect the required setting or retrieving movements of the anchoring assembly. Inherent in many prior art anchoring assemblies is the danger of premature release of the assembly from the mechanical linkage before the assembly is securely anchored within the surrounding well conduit. Such dangers are increased where the components required to effect the setting and release movements are complex and may require difficult, or elaborate surface controlled manipulations. In' addition, where a large number of interrelated, closely fitting components are required to provide the desired setting and retrieval operations of the anchoring assembly, the danger of malfunction and the difficulty in setting and retrieving are increased in relation to the number and complexity of such interrelated parts.

A danger which is particularly associated with pump-down equipment is the possibility that such equipment may lodge so firmly in a deviated or restricted part of the well conduit that the pressure differential developed across the assembly is insufficient to drive it axially into position or to return it to the surface. Unless suitable provision is employed in such pump-down devices, conventional general purpose fishing tools may be required to extract lodged assemblies which may necessitate substantial expenditures for equipment and personnel in addition to producing significant losses of production time.

SUMMARY OF THE INVENTION The anchoring assembly of the present invention is designed to be pumped down to a sub-surface location in a well conduit which extends into a pressurized formation. The anchoring member of the assembly includes radially movable dogs which may be moved into and locked in anchoring engagement with a collar recess formed in the conduit wall. Storm chokes, packers and other well equipment may be suspended from or secured to the anchoring assembly.

The anchoring assembly is driven downwardly through the conduit under the influence of a pressurized fluid such as a suitable gas supplied from the wellhead which acts against a positioning member releasably secured to the anchoring assembly. The positioning member is equipped with an annular resilient seal which forms a substantially continuous sliding seal with the surrounding conduit walls. When the desired subsurface location has been reached by the assembly, the well-head pressure is gradually reduced until the for mation pressure can drive the positioning member and attached anchoring member back upwardly through the conduit. This upward movement causes relative axial movement between components in the anchoring assembly which tends to urge the anchoring dogs radially outwardly. When a conduit recess registers with the outwardly urged dogs, the dogs extend into the recess which thereby permits further relative axial movement between components in the anchoring assembly to a position which prevents retraction of the dogs. The extended dogs engage the upper boundary of the conduit recess to prevent upward movement of the anchoring assembly. When a sufficient pressure differential is developed across the positioning member, a connecting shear pin is severed to permit the positioning member to separate from the fixed anchoring member and move upwardly to the well-head where it can be recovered. Locking means are included in the anchoring member to maintain it in its set posiiton. Safety latch locking elements prevent the anchoring and positioning members from separating until the anchoring dogs are fully expanded and locked into position.

When the anchoring member is in set position, the relative axial positions of the anchoring assembly components are fixed by a resilient snap ring which urges the components to a position where the anchoring dogs are prevented from radially retracting. In a modified form, a coil spring may be used by itself or in combination with a snap ring to provide the desired locking force.

Retrieval of the anchoring member from its set position is effected by pumping the positioning means equipped with a retrieving. head into locking engagement with the anchoring member. The retrieving head repositions the axial relationship of the movable components in the anchoring member to permit retraction of the locking dogs. Subsequent reduction in the wellhead pressure permits the formation pressure to drive the positioning member and attached anchoring member upwardly to the well-head where the assembly may be recovered.

Emergency retrieving means are included with the positioning member so that a wire-line or tubing string retrieving tool may be lowered into locking engagement with the positioning member to permit it to be withdrawn from the conduit by a force exerted through the wire-line or tubing string. A frangible plate included in the positioning member is ruptured by the emergency retrieving means to destroy the pressure seal existing axially across the positioning member.

From the following specification, the related drawings, and the Claims, it will be appreciated that the anchoring assembly of the present invention provides a simple, effective, mechanism for positioning an anchoring assembly at a sub-surface location in a well conduit without the need for a mechanical linkage such as a wire-line or tubing string. Recovery of the set anchoring assembly may also be accomplished by pressure drive without the need for a surface operated mechanical linkage. Moreover, the direct and simple operation and construction of the anchoring assembly ensures positive anchoring and retrieval of the anchoring member at the desired sub-surface location. These and other features and advantages of the present invention will be more fully appreciated from the following specification, the related drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical, quarter-sectional view of an anchoring assembly of the present invention in its unset running position;

FIG. 2 is a view similar to FIG. 1 illustrating the anchoring assembly moving upwardly past a first collar recess during the first stage of setting;

FIG. 3 illustrates the anchoring member components moved to the set position by the positioning member;

FIG. 4 illustrates the anchoring member in fully set condition with the positioning member moving to the surface under the influence of the formation pressure;

FIG. 5 is a vertical, quarter-sectional view illustrating the anchoring assembly in released position secured to a retrieving head carried by the positioning member;

FIG. 6 is a vertical, quarter-sectional view illustrating a modified form of the anchoring assembly employing a coil spring for preventing relative axial movement of components when the anchoring member is in set condition;

FIG. 7 illustrates the emergency retrieval of the anchoring assembly by a mechanical linkage extending from the well surface;

FIG. 8 is a partial vertical elevation in diagrammatic form illustrating the anchoring member of the present invention anchoring a storm choke in a well conduit;

FIG. 9 is a cross-sectional view taken along the line 99 of FIG. 1;

FIG. 10 is a cross-sectional view taken along the line 10-1O of FIG. 1;

FIG. 11 is a cross-sectional view taken along the line ll-l1 of FIG. 1; and

FIG. 12 is a partial, quarter-sectional view illustrating the operation of the retrieving head employed with the positioning member of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference first to FIG. 8, the anchoring member of the present invention is indicated generally at 10 anchored within a collar recess R formed in a well conduit C which extends into a subterranean formation -F. The anchoring member is employed to position equipment S within the conduit C. The equipment S may be a storm choke which is employed to prevent uncontrolled flow of fluids or gases from the formation F in a well known manner. The formation F may be a gas storage reservoir or any other relatively high pressure area which communicates through a conduit with a relatively lower pressure area.

The upper portion of the conduit C includes a conventional lubricator indicated generally at L which is employed to insert the anchoring assembly and attached equipment S into the well conduit C while the latter is under relatively high pressure. The lubricator L includes a removable top T and a valved, pressure supply line P is connected into the upper portion of the lubricator L and a large valve L is included at the lower portion. Conventional pipe lines G connect with the upper portion of the conduit C and are employed to convey the oil or gas produced from the formation F to remote storage, use, or transportation facilities.

Operation of the lubricator L is conventional and when equipment is to be inserted into the conduit C, the valve L is closed, the top T is removed and the equipment is lowered into the barrel of the lubricator L. The top T is replaced and the valve L is opened after the valves in the pipe lines G are moved to closed position. A suitable high pressure fluid, preferably a gas, is introduced through the high pressure supply line P and when the supply pressure is sufficiently greater than the formation pressure, the anchoring assembly and attached equipment is driven downwardly through the conduit C. Recovery of the pump-down equipment is effected by reducing the well-head pressure so that the formation pressure may move the equipment upwardly. Where the equipment can not be moved by the driving force developed by a pressure differential, it may be necessary to employ a wire-line or tubing string operated retrieving device. In the latter event, the wellhead equipment is provided with suitable stuffing boxes or other means (not illustrated) which permit the wireline or tubing string to be rotated or moved axially from the well surface without high pressure loss.

Referring now to FIG. II, the anchoring assembly of the present invention is indicated generally at A. The anchoring member 10 which forms a part of the assembly A is illustrated within the conduit C in unset condition as it appears when being pumped downwardly through the conduit by pressure supplied from the well surface. The upper portion of the anchoring assembly A is equipped with a releasable positioning member indicated generally at 11. The positioning member 11 forms a continuous plugging seal within the conduit C. This plugging seal is provided by a resilient, annular driving seal 12 which is adapted to slide against the walls of conduit C to form a sliding seal between a latching body 13 in the positioning means 11 and the surrounding walls of the conduit C. A frangible plate 14 and an annular O-ring l5 cooperate with the seal 12 to form a complete seal in the conduit C.

The annular seal 12 includes a circumferential groove 12a and a plurality of radial openings 12b which permit pressurized fluid to act behind the seal in an annular area indicated at 12c. The seal 12 functions as though it were two oppositely disposed swab cups. When pressure is supplied from the well surface, the upper portion of the seal indicated at 12 is depressed and the pressure fluid enters the bores 12b where it acts in the annular area to force the lower portion of the seal indicated generally at 12" against the walls of the conduit C. A resultant downwardly directed force is exerted on the positioning member 11 causing the entire assembly A to be driven down through the well conduit. A sliding seal is maintained by the pressure induced outward radial force exerted in the area 12c against the lower seal section 12". When the pressure below the seal 12 on the positioning member 11 is greater than that above the seal, the seal 12 functions in the manner previously described except that the section 12" is collapsed and the upper section 12' functions as a sliding seal driving the entire assembly upwardly through the conduit C.

A connecting sleeve 16 is threadably engaged to the lower end of the latching body 13 and extends downwardly into the anchoring member 10. A set screw 17 or other suitable means is employed to prevent relative rotational movement between the body 13 and sleeve 16 to prevent the two components from separating while in use.

The anchoring member is constructed in substantially tubular form from a composite body which includes an outer sleeve body 20 constructed of three threadedly connected segments including an upper sleeve segment 20a, a middle segment 20b, and a lower segment 20c. A setting sleeve 21 is concentrically disposed within the outer sleeve 20 and is adapted to be moved axially with respect to the sleeve 60 during the setting and retrieval functions to be described. The third member in the tubular anchoring body includes an inner retaining sleeve 22 which is concentrically disposed within the outer sleeve body 20 and within a portion of the setting sleeve body 21. As will be described, the retaining sleeve 22 is adapted to be moved axially with respect to both the outer sleeve 20 and setting sleeve 21 during the setting and retrieving operation of the anchoring assembly.

The connecting sleeve 16 is releasably secured to the tubular body of the setting member 10 by means of a severable shear pin 23 which extends from the upper end of the setting sleeve 21. With joint reference to FIGS. 1, 9, and 1 1, radially movable upper dogs 24 and lower dogs 25 carried respectively in the setting sleeve 21 and the retaining sleeve 22 mate with receiving recesses in the connecting sleeve 16 and cooperate with the shear pin 23 to prevent relative axial movement between the connecting sleeve, retaining sleeve, and setting sleeve. The dogs 24 are equipped with circumferentially developed wings 24a which limit inward radial movement of the dogs in the sleeve 21. Similar wings 25a formed on the dogs 25 limit inward radial movement of the dogs in the sleeve 22. The anchoring member 10 also includes an upper protective packing seal 26 and a lower pack-off seal 27 which function in a manner to be described. FIGS. 1 and 10 illustrate a plurality of radially movable anchoring dogs 28 extending through windows 29 formed in the outer body sleeve segment 20b to provide the desired anchoring engagement with the collar recess R formed in the conduit C. Outward radial movement of the anchor dogs is limited by circumferentially extending wings 28a which engage retaining shoulders 29a formed behind the windows 29.

The lower body segment 20c is connected to well equipment S which is to be anchored in the well conduit by the anchoring member 10.

Referring jointly to FIGS. 1-4, FIG. 1 illustrates the anchoring assembly being pumped downwardly through the conduit C, FIG. 2 illustrates the anchoring assembly A moving upwardly through the conduit with the anchoring dogs 28 in registry with the first collar recess R encountered in the upward travel, FIG. 3 illustrates the initial upward movement of the positioning member 11 away from the anchoring member 10 following initial setting of the member 10, and FIG. 4 illustrates the anchoring member and positioning member completely separated with the anchoring member being set in the collar recess R and the positioning member traveling to the well surface to be recovered.

In the initial setting position illustrated in FIG. 2, the upward movement of the positioning member 11 is resisted by the frictional engagement of the seal 27 with the well conduit C and by weight of the suspended equipment S. This initial resistance to movement by the anchoring member tends to hold the outer sleeve body 20 relatively stationary with respect to the upwardly moving connector sleeve 16, setting sleeve 21, and retaining sleeve 22. Before the anchoring dogs 28 are in registry with the collar recess R, inclined surfaces engage each other in cooperating grooves and recesses formed between the anchoring dogs 28 and setting sleeve 21 and urge the anchoring dogs outwardly into engagement with the internal wall of the conduit C. Radial projections 28b extending from the outer surfaces of the anchoring dogs 28 engage the conduit wall and limit the outward radial movement of the anchoring dogs to maintain the groove and recess engagement be tween the anchoring dogs and the setting sleeve which in turn prevents upward movement of the setting sleeve 21 relative to the outer body sleeve 20. When the projections 28b register with the collar recess R, the anchoring dogs 28 are permitted to move radially outwardly which frees the setting sleeve 21 from locking engagement with the anchoring dogs permitting the components to move into the relative positions illustrated in FIG. 2. Continued upward movement of the outer body 20 is prevented by engagement of the projections 28b with the upper boundary of collar recess R and the ridge-to-ridge registery between the anchoring dogs 28 and setting sleeve 21 prevent the anchoring dogs from retracting radially. By this means, the outer body is prevented from moving axially upwardly and when a sufficient pressure differential is developed across the positioning member 1 1, the shear pin 23 severs to permit the positioning member to continue to move upwardly. The upper position of the setting sleeve 21 permits the upper dogs 24 to be expanded radially outwardly and the initial upward movement of the positioning member and attached connecting sleeve 16 draws the internal retaining sleeve 22 upwardly until the lower anchoring dogs 25 drop into a receiving recess in the setting sleeve 21. This positioning of the various components is illustrated in FIG. 3 and once the components have been so moved, the positioning member 11 is free to completely separate from the anchoring member 10.

With the retaining sleeve 22 in the position illustrated in FIG. 3, a resilient snap ring 30 carried by the sleeve 22 expands radially into a recess formed on the internal wall of the central outer body section 20b. In this latter position, the snap ring 30 resists downward axial movement of the retaining sleeve 22 which in turn prevents the setting sleeve and anchoring dogs from being moved to a position which would permit the anchoring dogs to retract radially. FIG. 6 illustrates a modified locking means which employs a coil spring to resist downward movement of the sleeve 22 with respect to the sleeve 20. If desired, the spring 130 may be employed alone or in combination with the split ring 30.

As best illustrated in FIGS. 3 and 4, in the set position the setting sleeve 21 is prevented from moving upwardly by virtue of the engagement between the upper end of setting sleeve 21 with the internal shoulder formed in sleeve section 20a. Downward movement of the setting sleeve with respect to the outer body 20is prevented by engagement of the dogs 24 with the internal shoulder formed by the upper end of sleeve section 20b. The dogs 24 in turn are held in extended position by a radial lip 22 projecting outwardly from the upper end of the retaining sleeve 22. Dogs 25 function as a last safety mechanism or tattle tale preventing separation of the anchoring and positioning members until the dogs 25 has been extended into a setting sleeve recess 21a. The cooperation of the three sleeves in the anchoring member prevent the dogs 25 from registering with recess 21a until the anchoring dogs 28 have been fully extended into anchoring engagement with a conduit recess. The continued upward movement of the positioning member 11 and the attached connecting sleeve 16 from the position illustrated in FIG. 2 forces adjacent inclined surfaces on the connecting sleeve and dogs 25 together which in turn urges the dogs radially outwardly into the setting sleeve recess 21a. Further upward movement of the sleeve 22 with respect to the sleeve 21 is thus prevented and connecting sleeve 16 may then be moved axially upwardly into the position illustrated in FIG. 4 where it is free from the anchoring member 10. Even in its radially innermost position, the dogs 25 extend radially away from the outer wall of the sleeve 22 and prevent the latter sleeve from moving upwardly with respect to the sleeve 21 after the dogs 25 are in recess 21a. As previously noted, when the components of the anchoring assembly 10 are in set position, the snap ring 30 expands radially into a receiving recess in the central sleeve section 20b to prevent relative downward movement between the retaining sleeve 22 and the outer body sleeve 20. Thus, with the components in the position illustrated in FIG. 4, the anchoring member 10 and attached equipment S are securely engaged with the recess R. In this latter position, the central bore of the anchoring member is open to permit axial flow through the assembly. The annular protective seal 26 prevents sediment and debris from dropping into the annular area between the outer body sleeve 20 and the surrounding well conduit C to protect the working components of the anchoring member and to prevent such materials from accumulating about the assembly. In the set position, a pair of axially spaced, resilient O-ring seals 31 and 32 are positioned axially above and below radial bores 20b formed in the outer body sleeve section 20b. In the latter position, a complete seal is formed in the area 27b so that the seal 27 functions to provide a sealing pack off between the outer body section 20b and the surrounding well conduit C.

Retrieval of the anchoring member 10 will now be described with reference to FIGS. and 12. When it is desired to retrieve the anchored assembly from its sub-surface position within the well conduit C, the connecting sleeve 16 on the positioning section 11 is replaced by a retrieving head indicated generally at 40. The retrieving head 40 includes a lower shoe 41 threadedly engaged to the bottom of a latch mounting sleeve 42 which in turn is trheadedly engaged to a connecting sub 43 secured to the latching body 13. A latching collar 44 mounted about the locking sleeve 42 for axial movement thereover includes a plurality of downwardly extending resilient fingers 45 with enlarged heads 45a formed at their lower ends. The upper internal portion of the collar 44 includes a plurality of circumferentially developed teeth 45' each of which includes a lateral, downwardly facing shoulder 45c and a slanted, upwardly facing shoulder 45d. Downward axial movement of the collar 44 over the sleeve 42 is limited by engagement of the lowermost shoulder 45c against a radial sleeve enlargement 42a. Upward movement of the collar 44 on the sleeve 42 is limited by engagement of the collar with the lower end of a protective guard collar 46 which in turn is secured to the sleeve 42 by means of a severable shear pin 47. Centralizing ribs 46a extend radially outwardly from the protective collar 46. The collar 46 covers a resilient split ring 48 having circumferentially developed teeth 48 each of which includes a plurality of lateral upwardly directed shoulders 48a and a plurality of slanted, downwardly directed shoulders 48b.

The retrieval operation of the anchoring assembly is initiated by introducing the positioning member 1 l and attached retrieval head 40 into the conduit C through the lubricator L in the manner previously described. Under the influence of the well-head pressure, the positioning means is lowered to the anchoring member 10 until the lower shoe 41 enters the top of sleeve section 20a. The upper axial end of the section 20a is beveled inwardly to assist in directing the shoe into receiving position within the section. As best illustrated in FIG. 12, the enlarged heads 45a of fingers 45 engage the beveled surface on section 20a causing the collar 44 to remain stationary as the sleeve 42 continues to move downwardly through the member 10. When the upper end of collar 44 engages the lower end of protective collar 46, the downward movement of the body 42 is transmitted to the fingers 45 forcing the heads 45a against the beveled surface of section 20a and causing them to bend radially inwardly in the manner shown in FIG. 12. In the latter position, the heads 45a are permitted to move downwardly past the initial restriction formed in the upper end of section 20a and continued lowering of member 11 moves the heads into registry with an internal sleeve recess 20a. Simultaneously, a collar 41a severably secured to the lower shoe 41 by a shear pin 41bengages an internal shoulder 22a formed in the retaining sleeve 22. The downward force exerted by the positioning segment 1 1 overcomes the restraining force of lock ring 30 causing it to be moved radially inwardly into the receiving recess in sleeve 22 whereupon the sleeve 22 may continue to move downwardly under the force exerted by the positioning member 11. When lip 22 engages an inwardly developed shoulder on the setting sleeve 21, continued downward movement of the retaining sleve draws the setting sleeve downwardly so that the ridges on the internal surface of the dogs 28 may drop into the recesses formed on the external surface of the setting sleeve 22. In this latter position, illustrated in FIG. 5, the anchoring member 10 is free from anchoring engagement with the recess R and the enlarged heads 45a are locked into the recesses 20a by the sleeve 42. The well-head pressure may then be reduced to the point required to permit the formation pressure to drive the positioning member 11, attached anchoring assembly and equipment S to the well surface.

If the anchoring assembly 10 should become lodged in the well conduit C during this retrieval operation, the positioning member 11 may be separated and removed by increasing the surface pressure to move the positioning member back downwardly through the stationary anchoring member 10. When sufficient force is developed, shear pins 4lb and 47 will sever permitting the sleeve 42 to continue to move downwardly until the teeth 45 engage and ratchet over the exposed teeth 48. This is effected when the sloping shoulders 45d engage the sloping shoulders 48b causing the split ring 48 to be moved radially inwardly. The reverse movement between the ring 48 and collar 44 is prevented by the engagement of the flat shoulders 45c and 48a. In this latter position, the reduced diameter portion 42' of sleeve 42 is coincident with the enlarged heads 45a so that the heads are free to bend radially inwardly out of the recess a thereby freeing the positioning member 11 so that it may be recovered at the surface.

FIG. 7 illustrates retrieval of the positioning member 11 and attached anchoring member 10 by means of a retrieval head 140 connected to a tubing string T. If the anchoring assembly including the positioning means 11 becomes anchored or lodged in the conduit C and cannot be moved upwardly through the conduit C under the influence of the formation pressure, the head 140 is lowered from the well surface through a suitable lubricator until a shoe 141 carried at the bottom of the retrieving head engages the frangible plate 14. Resilient fingers 145 carried in a locking collar 144 and having enlarged heads 145a simultaneously latch into the recess 20a in the manner previously described with reference to retrieving head 40. The lower shoe 141 is driven against the frangible plate 14 causing it to break which in turn destroys the pressure barrier previously existing across the setting device 11. Thereafter the positioning assembly 11 and anchoring assembly 10 may be withdrawn to the surface by raising the tubing string T.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

1 claim:

1. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising:

a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit, said anchoring means further including:

i. an axially extending, substantially tubular body of composite construction;

ii. radially movable engagement means carried by said body and disposed for outward radial movement into anchoring engagement with said well conduit for preventing relative axial movement between said anchoring means and said well con- 7 duit;

iii. setting means included in said body for selectively moving said engagement means radially into and out of engagement with said well conduit;

iv. locking means included in said body for locking said engagement means in the radially outwardly position in anchoring engagement with said well conduit; and

v. anchor seal means carried by said body for forming a seal between said body and said surrounding well conduit;

b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit;

c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and

d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.

2. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising:

a. remotely anchoring means for engaging and disengaging the intemal surface of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit, said anchoring means having an axially extending, substantially tubular body of composite construction which includes:

i. an outer sleeve body;

ii. a setting sleeve body concentrically disposed within at least a portion of said outer sleeve body;

iii. a retaining sleeve body concentrically disposed within at least a portion of said setting sleeve body;

iv. engagement means including a plurality of radially movable dogs carried between said outer sleeve body and said setting sleeve body and being substantially fixed against axial movement with respect to said outer sleeve body, said dogs being operable for anchoring engagement with said well conduit for preventing relative axial movement between said anchoring means and said well conduit; and

v. locking means including cooperating recess and ridge means formed on the radially inner surfaces of said dogs and on the radially outer surface of said setting sleeve body with said setting body being movable axially with respect to said dogs to first and second axial positions where in said first position, recess means in said dogs register with ridge means in said setting body to permit said dogs to move radially inwardly and where in said second position, ridge means in said dogs register with ridge means in said setting body to retain said dogs radially outwardly in anchoring engagement with said surrounding well conduit;

b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit;

c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and

d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.

3. An anchoring assembly as defined in claim 2 wherein the external surface of said dogs include radial projections for engaging the internal surface of said well conduit and for maintaining said dogs radially retracted in said anchoring means until said projections register with a recess in the wall of said well conduit.

4. An anchoring assembly as defined in claim 3 wherein:

a. said retaining sleeve body is movable between upper and lower axial positions by said positioning means; and

b. said setting sleeve body is locked in said second axial position with said dogs extended when said setting sleeve body is in said upper axial position.

5. An anchoring assembly as defined in claim 4 wherein said locking means includes a coil spring for resisting movement of said retaining sleeve body from said upper to said lower axial position.

6. An anchoring assembly as defined in claim 5 wherein said locking means further includes a resilient snap ring adapted to expand radially to further resist axial movement of said retaining sleeve from said upper axial position to said lower axial position.

7. An anchoring assembly as defined in claim 4 wherein said locking means includes a resilient snap ring adapted to expand radially to resist axial movement of said retaining sleeve from said upper axial position to said lower axial position.

8. An anchoring assembly as defined in claim 7 further including protective packing means extending radially from said tubular body to said well conduit at a point axially above said engagement means.

9. An anchoring assembly as defined in claim 8 further including second sealing means extending between said anchoring means and said well conduit for forming a seal between said anchoring means and said conduit.

10. An anchoring assembly as defined in claim'9 where said positioning means includes access means for engaging and locking into said' positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said anchoring means by movement exerted from the well surface through said linkage.

l 1. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising:

a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit; said anchoring means further including:

i. an axially extending, substantially tubular body of composite construction;

ii. radially movable engagement means carried by 65 said body and disposed for outward radial movement into anchoring engagement with said well conduit'for preventing relative axial movement between said anchoring means and said well conduit;

iii. setting means included in said body for selectively moving said engagement means radially 5 into and out of engagement with said well conduit;

iv. locking means included in said body for locking said engagement means in the radially outwardly position in anchoring engagement with said well conduit; and

v. protective packing means extending radially from said tubular body to said well conduit at a point axially above said engagement means;

b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit;

c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and

d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.

12. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit com- 30 prising:

a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit;

b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit;

c. access means included in said positioning means for engaging and locking on to said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said anchoring means by movement exerted from the well surface through said linkage;

d. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means, said first sealing means further including seal opening means operable by said mechanical linkage for permitting pressure equalization across said first sealing means; and

e. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.

13. An anchoring assembly as defined in claim 12 further including a frangible plate included in said seal opening means and adapted to be broken by said mechanical linkage for permitting pressure equalization across said first sealing means.

14. An anchoring assembly for well equipment comprising:

a. a tubular body for supporting a well tool in a well conduit;

b. friction means carried by said body for frictionally engaging said well conduit;

0. anchor elements mounted about said body for radial movement between extended and released positions respectively effecting anchoring engagement with and release from said well conduit;

d. a setting sleeve cooperating with said anchor elements carried by said body for relative axial movement therewith between positions extending and releasing said anchor elements;

e. pressure movable positioning means connected with said body for moving said body through said well conduit, said positioning means including access means for engaging and locking into said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said body by movement exerted from the well surface through said linkage; connecting means included with said positioning means for releasably connecting said positioning means to said tubular body;

g. first sealing means included with said positioning means for forming a seal between the areas in said well conduit above and below said first sealing means, said first sealing means further including a frangible plate adapted to be broken by said mechanical linkage for permitting pressure equalization across said first sealing means;

h. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means;

. safety latch locking elements initially securing said connecting means to said tubular body and only releasable from said connecting means to release and positioning means from said tubular body upon axial movement of said setting sleeve to said position extending said anchor elements into anchoring engagement with said well conduit; and j. pressure movable retrieving means engageable with said body and including means for moving said setting sleeve axially to said position releasing said anchor elements from anchoring engagement with said well conduit whereby said tubular body may be moved axially through said well conduit by said retrieving means 15. An anchoring assembly as defined in claim 14 wherein said friction means includes packing means extending between said body and said well conduit.

16. An anchoring means as defined in claim 14 wherein said safety latch locking elements include frangible locking means securing said connecting means to said setting sleeve for preventing release of said positioning means from said tubular body until said anchoring elements are in anchoring engagement with a recess in the wall of said well conduit.

17. A system for anchoring equipment in an elongate well conduit extending from a wellhead to a subsurface formation comprising:

a. a plurality of tubular conduit segments connected together at their ends to form an elongate well conduit having internal recesses at the juncture between adjoining segments;

b. a remotely operable anchoring means having radially movable dog means projectable into said recesses to prevent longitudinal movement of said anchoring means through said elongate conduit;

c. pressure driven positioning means movably disposed within said elongate well conduit and releasably secured to said anchoring means for moving said anchoring means through said elongate conduit;

d. actuating means included with said anchoring means for urging said dog means radially outwardly when said positioning means and said attached anchoring means are moved upwardly through said elongate conduit whereby said dog means are projected into one of said recesses;

e. locking means operable when said dog means have projected into one of said recesses for retaining said dog means in a radially extended position in anchoring engagement with said elongate conduit;

f. release means operable after said dog means project into one of said recesses for releasing said positioning means from said anchoring means whereby said positioning means may be moved through said elongate conduit to the wellhead;

g. access means included with said positioning means for engaging said locking onto said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means by movement exerted from the well surface through said linkage; and

h. selectively openable seal opening means included in said pressure driven positioning means for selectively permitting pressure equalization across said positioning means.

18. A system as defined in claim 17 wherein saidselectively openable seal opening means comprises a frangible plate adapted to be broken by said mechanical linkage.

19. A system as defined in claim 17 further including pressure movable retrieving means engageable with said anchoring means for releasing said anchoring means from said elongate well conduit whereby said anchoring means may be moved axially through said elongate conduit by said retrieving means.

20. A system as defined in claim 19 wherein said retrieving means includes access means for engaging and locking onto said retrieving means with a mechanical linkage extending from the well surface.

21. A system as defined in claim 20 wherein said retrieving means includes selectively openable seal opening means for selectively permitting pressure equalization across said retrieving means.

22. A system as defined in claim 21 wherein said seal opening means in said retrieving means includes a frangible plate means adapted to be broken by said last mentioned mechanical linkage. 

1. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising: a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit, said anchoring means further including: i. an axially extending, substantially tubular body of composite construction; ii. radially movable engagement means carried by said body and disposed for outward radial movement into anchoring engagement with said well conduit for preventing relative axial movement between said anchoring means and said well conduit; iii. setting means included in said body for selectively moving said engagement means radially into and out of engagement with said well conduit; iv. locking means included in said body for locking said engagement means in the radially outwardly position in anchoring engagement with said well conduit; and v. anchor seal means carried by said body for forming a seal between said body and said surrounding well conduit; b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit; c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.
 2. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising: a. remotely anchoring means for engaging and disengaging the internal surface of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit, said anchoring means having an axially extending, substantially tubular body of composite construction which includes: i. an outer sleeve body; ii. a setting sleeve body concentrically disposed within at least a portion of said outer sleeve body; iii. a retaining sleeve body concentrically disposed within at least a portion of said setting sleeve body; iv. engagement means including a plurality of radially movable dogs carried between said outer sleeve body and said setting sleeve body and being substantially fixed against axial movement with respect to said outer sleeve body, said dogs being operable for anchoring engagement with said well conduit for preventing relative axial movement between said anchoring means and said well conduit; and v. locking means including cooperating recess and ridge means formed on the radially inner surfaces of said dogs and on the radially outer surface of said setting sleeve body with said setting body being movable axially with respect to said dogs to first and second axial positions where in said first position, recess means in said dogs register with ridge means in said setting body to permit said dogs to move radially inwardly and where in said second position, ridge means in said dogs register with ridge means in said setting body to retain said dogs radially outwardly in anchoring engagement with said surrounding well conduit; b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit; c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby sAid positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.
 3. An anchoring assembly as defined in claim 2 wherein the external surface of said dogs include radial projections for engaging the internal surface of said well conduit and for maintaining said dogs radially retracted in said anchoring means until said projections register with a recess in the wall of said well conduit.
 4. An anchoring assembly as defined in claim 3 wherein: a. said retaining sleeve body is movable between upper and lower axial positions by said positioning means; and b. said setting sleeve body is locked in said second axial position with said dogs extended when said setting sleeve body is in said upper axial position.
 5. An anchoring assembly as defined in claim 4 wherein said locking means includes a coil spring for resisting movement of said retaining sleeve body from said upper to said lower axial position.
 6. An anchoring assembly as defined in claim 5 wherein said locking means further includes a resilient snap ring adapted to expand radially to further resist axial movement of said retaining sleeve from said upper axial position to said lower axial position.
 7. An anchoring assembly as defined in claim 4 wherein said locking means includes a resilient snap ring adapted to expand radially to resist axial movement of said retaining sleeve from said upper axial position to said lower axial position.
 8. An anchoring assembly as defined in claim 7 further including protective packing means extending radially from said tubular body to said well conduit at a point axially above said engagement means.
 9. An anchoring assembly as defined in claim 8 further including second sealing means extending between said anchoring means and said well conduit for forming a seal between said anchoring means and said conduit.
 10. An anchoring assembly as defined in claim 9 where said positioning means includes access means for engaging and locking into said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said anchoring means by movement exerted from the well surface through said linkage.
 11. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising: a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit; said anchoring means further including: i. an axially extending, substantially tubular body of composite construction; ii. radially movable engagement means carried by said body and disposed for outward radial movement into anchoring engagement with said well conduit for preventing relative axial movement between said anchoring means and said well conduit; iii. setting means included in said body for selectively moving said engagement means radially into and out of engagement with said well conduit; iv. locking means included in said body for locking said engagement means in the radially outwardly position in anchoring engagement with said well conduit; and v. protective packing means extending radially from said tubular body to said well conduit at a point axially above said engagement means; b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit; c. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means; and d. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a preSsure differential developed axially across said first sealing means.
 12. An anchoring assembly for anchoring well equipment within a surrounding tubular well conduit comprising: a. remotely operable anchoring means for engaging and disengaging the internal surfaces of said surrounding well conduit to respectively anchor and release said anchoring assembly in said well conduit; b. pressure responsive positioning means connected with said anchoring means for axially moving said anchoring means through said well conduit; c. access means included in said positioning means for engaging and locking on to said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said anchoring means by movement exerted from the well surface through said linkage; d. first sealing means included with said positioning means for forming a pressure seal in said conduit between the areas above and below said first sealing means, said first sealing means further including seal opening means operable by said mechanical linkage for permitting pressure equalization across said first sealing means; and e. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means.
 13. An anchoring assembly as defined in claim 12 further including a frangible plate included in said seal opening means and adapted to be broken by said mechanical linkage for permitting pressure equalization across said first sealing means.
 14. An anchoring assembly for well equipment comprising: a. a tubular body for supporting a well tool in a well conduit; b. friction means carried by said body for frictionally engaging said well conduit; c. anchor elements mounted about said body for radial movement between extended and released positions respectively effecting anchoring engagement with and release from said well conduit; d. a setting sleeve cooperating with said anchor elements carried by said body for relative axial movement therewith between positions extending and releasing said anchor elements; e. pressure movable positioning means connected with said body for moving said body through said well conduit, said positioning means including access means for engaging and locking into said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means and said body by movement exerted from the well surface through said linkage; f. connecting means included with said positioning means for releasably connecting said positioning means to said tubular body; g. first sealing means included with said positioning means for forming a seal between the areas in said well conduit above and below said first sealing means, said first sealing means further including a frangible plate adapted to be broken by said mechanical linkage for permitting pressure equalization across said first sealing means; h. sliding seal means included with said first sealing means for forming a substantially continuous sliding seal between said positioning means and said well conduit whereby said positioning means may be driven axially through said well conduit under the influence of a pressure differential developed axially across said first sealing means; i. safety latch locking elements initially securing said connecting means to said tubular body and only releasable from said connecting means to release and positioning means from said tubular body upon axial movement of said setting sleeve to said position extending said anchor elements into anchoring engagement with said well conduit; and j. pressure movable retrieving means engageable with said body and including means for moving said setting sleeve axially to said position releasing said anchor elements from anchoring engagement with said well conduit whereby said tubular body may be moved axially through said well conduit by said retrieving means
 15. An anchoring assembly as defined in claim 14 wherein said friction means includes packing means extending between said body and said well conduit.
 16. An anchoring means as defined in claim 14 wherein said safety latch locking elements include frangible locking means securing said connecting means to said setting sleeve for preventing release of said positioning means from said tubular body until said anchoring elements are in anchoring engagement with a recess in the wall of said well conduit.
 17. A system for anchoring equipment in an elongate well conduit extending from a wellhead to a subsurface formation comprising: a. a plurality of tubular conduit segments connected together at their ends to form an elongate well conduit having internal recesses at the juncture between adjoining segments; b. a remotely operable anchoring means having radially movable dog means projectable into said recesses to prevent longitudinal movement of said anchoring means through said elongate conduit; c. pressure driven positioning means movably disposed within said elongate well conduit and releasably secured to said anchoring means for moving said anchoring means through said elongate conduit; d. actuating means included with said anchoring means for urging said dog means radially outwardly when said positioning means and said attached anchoring means are moved upwardly through said elongate conduit whereby said dog means are projected into one of said recesses; e. locking means operable when said dog means have projected into one of said recesses for retaining said dog means in a radially extended position in anchoring engagement with said elongate conduit; f. release means operable after said dog means project into one of said recesses for releasing said positioning means from said anchoring means whereby said positioning means may be moved through said elongate conduit to the wellhead; g. access means included with said positioning means for engaging said locking onto said positioning means with a mechanical linkage extending from the well surface for retrieval of said positioning means by movement exerted from the well surface through said linkage; and h. selectively openable seal opening means included in said pressure driven positioning means for selectively permitting pressure equalization across said positioning means.
 18. A system as defined in claim 17 wherein said selectively openable seal opening means comprises a frangible plate adapted to be broken by said mechanical linkage.
 19. A system as defined in claim 17 further including pressure movable retrieving means engageable with said anchoring means for releasing said anchoring means from said elongate well conduit whereby said anchoring means may be moved axially through said elongate conduit by said retrieving means.
 20. A system as defined in claim 19 wherein said retrieving means includes access means for engaging and locking onto said retrieving means with a mechanical linkage extending from the well surface.
 21. A system as defined in claim 20 wherein said retrieving means includes selectively openable seal opening means for selectively permitting pressure equalization across said retrieving means.
 22. A system as defined in claim 21 wherein said seal opening means in said retrieving means includes a frangible plate means adapted to be broken by said last mentioned mechanical linkage. 